METHOD OF PRODUCTING PLANAR AVALANCHE PHOTODIODE

• Main Authors: LEE, KI WON, YANG, KYOUNG HOON
• Format: Patent
• Language: English; Korean
• Published: 16.04.2014
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The present invention relates to a method of fabricating a planar avalanche photodiode through a single etching process and a single diffusion process. An etch mask layer is formed on an InP buffer layer, an InGaAs light absorption layer, an InGaAsP grading layer, an InP electric field control layer, and an InP layer formed on the entire surface of an InP substrate. A wet etch area of the InP layer corresponding to a photodetecting region and having the etch mask layer is wet-etched. An anti-diffusion layer is formed on the etched InP layer and a diffusion source is diffused, thereby simultaneously forming a guard ring, an active region, a floating guard ring, and an amplified layer. A surface protection and reflection-blocking layer is formed on the InP layer having all of the guard ring, the active region, the floating guard ring, and the amplified layer. An upper electrode layer is formed in an exposure area of the surface protection and reflection-blocking layer, and a lower electrode layer is formed on the InP substrate. The amplified layer can be easily adjusted by simply adjusting an etch depth and a diffusion depth, thereby improving the reproducibility. A required etch shape can be obtained regardless of the etch direction. A soft and large curvature is made to prevent an electric field from being concentrated on a border and an edge. Since the performance of the avalanche photodiode is not degraded due to the etch, the device having superior performance can be fabricated. [Reference numerals] (AA) Start; (BB) End; (S501) Form etch mask layer; (S502) Etch wet etch area; (S503) Form anti-diffusion layer; (S504) Diffusion of diffusion source; (S505) Surface protection and reflection-blocking layer; (S506) Form upper electrode layer; (S507) Form lower electrode layer